Abstract: To explore the amelioration effect of anionic surfactant-based soil crust remover on soil structure and yield improvement of maize in sloping upland red soil, a field experiment was carried out on sloping red soil with maize cultivar Zhengdan 958 as test material. Treatments included blank control (CK1), clean water control (CK2), and spraying of conditioner diluted 500-fold (T500), 750-fold (T750) and 1 000-fold (T1000). The results showed that maize yield under T750 was the highest, which was significantly increased by 33.1% compared with CK2. The yield of T500 was second, significantly 17.5% higher than CK2. Due to insufficient active ingredients, the yield of T1000 showed no significant difference from CK2. After two sprays, T500 obviously reduced the average soil penetration resistance in the 1.0-45.0 cm soil layer. Maize yield was significantly negatively correlated only with penetration resistance in the 1.0 cm soil layer (P<0.05). Short-term spraying of anionic surfactant exerted no significant effects on soil pH, organic carbon, total nitrogen and soil aggregate fractions, which could be attributed to strong stability of red soil colloid, surface spraying mode and short experimental period. This conditioner alleviated surface soil crust and reduced mechanical resistance to root growth by lowering surface tension of soil solution and regulating electrostatic balance of clay particles, thereby increasing maize yield. The 750-fold dilution was the optimal application concentration for maize in sloping upland red soil.

Key words: soil crust remover product, anionic surfactant, sloping upland red soil, soil penetration resistance, maize yield